New breast cancer study shows hormonal therapy not enough

Many postmenopausal women with hormone-dependent breast cancer (requires estrogen and/or progesterone to grow) may be undertreated if they do not receive chemotherapy in addition to hormonal therapy after surgery, according to a Loyola University Health System, Maywood, Ill., study.

Loyola’s Dr. Kathy S. Albain presented the results of a 10-year follow-up of The Breast Cancer Intergroup of North America Trial 0100 at the late breaking session of the San Antonio Breast Cancer Symposium annual meeting here today. “The research shows that, in many cases, tamoxifen or other hormonal therapy alone is not optimal,” said principal investigator and first author Albain, professor, division of hematology/oncology, Department of Medicine, Loyola University Chicago Stritch School of Medicine, Maywood, Ill. “Overall, chemotherapy helped stop the cancer from recurring in postmenopausal women with receptor-positive breast cancer that has spread to the lymph nodes,” said Albain. “This survival advantage was greatest when tamoxifen followed chemotherapy, rather than given concurrently.

“Ten-year disease-free-survival estimates were 48 percent for those treated with tamoxifen alone; 53 percent for concurrent chemohormonal therapy; and 60 percent for sequential therapy,” said Albain, director, Breast Research Program; co-director of the multidisciplinary Breast Oncology Center; and director of the Thoracic Oncology Program, Cardinal Bernardin Cancer Center, Loyola University Health System, Maywood, Ill.

Albain and colleagues conducted a 10-year follow-up of 1,477 patients. A total of 550 patients received concurrent chemohormonal therapy (CAFT) (cyclophosphamide, doxorubicin, 5-fluorouracil, tamoxifen); another 566 patients received sequential chemohormonal therapy (CAF-T); and 361 patients received tamoxifen alone. “Long-term follow-up of this large North American trial confirms that chemotherapy benefits postmenopausal women with hormone-dependent breast cancer,” said Albain. “We discovered that women with very high levels of estrogen receptor in their tumors can probably avoid chemotherapy, but those with lower or intermediate levels benefit from it over and above tamoxifen.

A second aspect of this study explored the use of various molecular markers measured on the breast tumor to predict the added value of chemotherapy. The purpose of this was to determine if the individual’s biologic profile on an individual tumor enables us to tailor therapy more specifically. “These results will help current breast cancer treatment in that we are moving to regimens tailored to the specific individual’s cancer and it will stimulate future research,” said Albain.

Co-authors of the study are K. S. Albain; W. Barlow; F. O’Malley; K Siziopikou; I-T Yeh; P. Ravdin; D. Lew; W. Farrar; G. Burton; S. Ketchel; C. Cobau; E. Levine; J. Ingle; K. Pritchard; A. Lichter; D. Schneider; M. Abeloff; I. C. Henderson; L. Norton; D. Hayes; S. Green; R. Livingston; S. Martino; C. K. Osborne; and D. C. Allred, The Breast Cancer Intergroup of North America, Loyola University Chicago Stritch School of Medicine, Maywood, Ill.

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The 27th Annual San Antonio Breast Cancer Symposium meeting at the Henry B. Gonzalez Convention Center, San Antonio, Tex., runs through December 11, 2004.